#include <stdio.h>

main()
{long i;
    int j;
    printf("Please input number;");
    scanf("%ld",&i);
    for(j=999;j>=100;j--)
    if(i%j==0){
        printf("The max factor with 3 digits in %ld is;%d,\n",i,j);
        break;
    }


    //吴昌源
}